Airplane



March 21, 1,28. R. F. HALL unrwm mea mgm. ma 5 simu-snm 2 March 27, 1928. 1,664,295

R, F. HALL MRPLANE Filed Aug. 2'9. 1923 5 Sheets-Sheet 5 V Mmh 27, 19m 1,664,295

R. F. HALL i AIRPLANE Filed Aug. 29..'1925 5 Sheets-Sheet 4 March 27, 1928.

R. F, HALL AIRPLANE Fiied Aug. 29. 1925 enorm",

Patented Mar. `27, 192s.

UNITED. STATES PATsNroFFlcE.

RANDOLPH F. HALL, OF ITHACA, NEW YORK, ASSIGNOR- OF TWENTY-FIVE ONE-HUN;- DREDTHS-TO THEODORE P. HALL, OF WALLINGFORD, CONN ECTIGUT, ANI) TWENTY- IEIV'lElI ONE-HUNDREDTHS TO. AGNEW E. LARSEN, OF BRYN ATHYN, PENNSYLVANIA.

AIRPLANE.

Application led August 29, 1923. Serial No. 659,987.

This invention relates to certain improvements in airplanes and more articularly to airplanes embodying the hdlicopter principle of vertical lift; and the nature and objects of the invention will be readily recognized and understood by those skilled in the C aeronautical art in the light of the following explanation and detailed description of the accompanying drawings illustrating what I at@ present consider to be the preferred em- .bodiments or aerodynamical and mechanical expressions of the invention from amon ova-.

` rious other forms, arrangements, com ina,-

Vtions and constructions of which the inven-- tion is capable within the spirit and scope thereof. v

The true vvertical lift or helicoptern type of heavier-than-air aircraft, hereinafter referred to generally as a helicopter or airplane of the helicopter type, is characterized generally by the derivation of direct vertical lift from an airscrew, propeller or similar medium mounted vfor rotation in a true horizontal plane around a vertical axis to develop sufficient static thrust in avertical plane to create a direct vertical lift capable of ,overcoming the weight of the airplane to permit of vertical ascent thereof, or of sustentation with the vert-ical thrust or lift and weight of the airplane balanced or equal and the vertical translational movement of the airplane zero. However, to secure the above result of vertical translationalmovement or ascent, and sustentation or hovering with the'vertical translational movement zero, it is essential that the power required to secure the necessary vertical thrust from the air screws or propellers be developed` with a minimum weight per horsepowenand the airscrews or propellers employed have a highefliciency to most economically utilize the power, as well vas to provide an efieient general design of aircraft embodying minimum weight-and parasite resistance with the requisite factor of safety for the type. There are, however, certain basic and fundamental problems of flight which must be solved by an airplane capable of vertical ascent, which problems are those of vertical lift; equilibrium; horizontal translational movement or flight in a horizontal plane; and descent or landing. In the helicopter type hereinbefore referred. to the problem of direct vertical lifthas been practically7 solved, with the advent of power plants of low Weight per horsepower, driving air screws or propellers of high aerodynamic eiiiclency with minimum power consumption to .develop a static thrust in a vertical plane resultmg in a direct vertical lift of suflicient magnitude to foverbalance or overcome the Weight of the airplane and permit of vertical translational movement or vertical ascending flight of an airplane of this direct vertical lift or helicopter type. However, the problems of equilibriumand of horizontal translational movement or Hight and of control during horizontal movement present complex and involved conditions difficult of practical solution,and these conditions are due primarily to the large unbalanced forces actlng" on and created by the airscrews or propellers rotating in a horizontal plane with the resulting large inertia forces from such rotating massesgand secondarily dueto the design and structural difficulties encountered in the mounting and arrangement of the elements of an airplane of the helicopter or direct vertical lift type in attempting to secure equilibrium and horizontal translational movement land control thereof during horizontal'movement. i

Another of the fundamental problems encountered With an airplane of the true helicopter type, the solution of which is vital and essentialA to practical operation and flight, isthe verticalpdescent or landing of such types of airplanes. Descent or landing may be accomplished with an airplane of the helicopter type referred to, by proper control of the power driving the airscrews or propellrs, so that the weight of the craft o verbalances or exerts a greater force than the propeller thrust and results in the airplane descending vertically. However, in the event of failure of the power the descent of the airplane cannot be controlled or checked and a fall out of control results. Various attempts-have been made to solve this problem by the provision of aerofoils or gliding surfaces, or by vdesigning and a1'- ran ing the airscrews or propellers to form sur aces for sustaining the helicopter in a glide, if the pow-er fails, as well as by the provision of various other means and devices for securing the required results, but' a practical solution of this problem which will retain in the helicopter or directvertical lift type of airplane the required aeiodynamical ellieiency and performance in operat1on and flight is dilicult' due to the complex aerodynamical, design and structural problems which must be overcome.

The 'present invent-ion is directed to the provision of a practical and aerodynamlcally efficient type of air plane capable of translational movement in a vertical plane or vertical ascent, and of a horizontal translational movement er horizontal flight, in which type of airplane the problem of vertical lift is solved in a more elllcient manner than in the true helicopter type hereinbefore referred to, which derives the entire vertical lift by the` direct thrust developed vfrom an airscrew or propeller; and the provision of such type of airplane in which `the further fundamental problems encountered in the helicopter type, of equilibrium; horizontal translational movement `or horizontal flight, and the control during horizontal flight; and descent or landing, are etliciently solved to produce a type and design of airplane embodying the aerodynamic and flight characteristics of both the helicopter type and the conventional type of airplane with the wellknown inherent advantages of each type.

One of thev main features and fundamental characteristics .of the invention is the mounting and arrangement of an airscrew pr propeller of high etliciency capable of a maximum static thrust at a low power output, so as to develop a thrust 'having a horizontal component and 'a vertical component, and the mounting of an aerofoil or lift surface in and so disposed with respect -to the displacement flow or so called slipstream of the propeller as to be acted upon thereby and create an additional force substantially equal to and balanced by the propeller thrust and having a vertical or lift component which together with the vertical lift component of the propeller thrust will maintain equilibrium and create a resultant vertical lift of greater magnitude than the propeller thrust is capable of developing alone. Due to the foregoing characteristic of the invention the problem of vertical lift and equilibrium is solved in a more eflicient manner than, in the true helicopter type, as agreater lift can be developed with an increase in performance or permitting a re-h duction in power with resulting decrease in weight. i

Another 'characteristic of the invention resides in applying the foregoing principle and solution of the vertical lift andequilibrium problems to an airplane of general conventional design, by mounting the propeller or propellers at an angle to the normal horizontal axis of the airplane approximately midway between the horizontal and the vertical, to develop a thrust having a horizontal or tractive component and a vertical or lift component, and by adjustably mounting and arranging the supporting surface or wing cellule in the displacement flow of the propeller or propellers so aste create an additional force substantially balancing the propeller thrust to maintain equilibrium and having a vertical coniponent which with the vertical component of the propeller thrust develops a resultant vertical lift capable of sustaining the air plane or of permitting vertical translational movement or vertical ascent with the airplane in substantially normal horizontal flight position. An airplane embodying these characteristics is capable of vertical ascent, or of horizontal translational movement or flight by proper adjustment of the wing cellule in the displacement flow or by tilting the airplane downwardly to increase the horizontal thrust component, or by a combination of both operations.y In horizontal flight the problems inherent in the helicopter type are overcome as the unbalanced forces encountered with airscrews rotating in a horizontal plane are eliminated and directional, longitudinal and lateral control is accomplished in the usual manner by the conventional tail assembly or empennage on the body or fuse-I lage and aileronson the Wing cellule. Equilibrium and control are further aided by adjustment of the supporting surface or wing cellule in the propeller displacement flow. The helicopter descent or landing problem is eliminated without material decrease of vertical ascent performance and efiiciency in an airplane having the foregoing characteristics, as in the event of power failure the air plane can be landed in the conventional glide under colnplete control.

Another characteristic of the invention is in the mounting of an aerofoil or aerofoils in the propeller displacement flow in accordance with the foregoing principle'of the invention, so that each aerofoil is positioned and set at an angle of incidence relative to the direction of flow acting thereon, and not relative to the axis of the propeller. By this characteristic of the invention, advantage is taken of the fact that the direction of the displacement flow is not the saine throughout and the maximum ellieiency and lift are obtained from an aerofoil so mounted therein.

Another characteristic of the invention` The design characteristics'of the pontoonslor floats is further such as to reduce and arrange the water contact l areas thereof so that a minimum'. of fluid viscosity must be overcome in a vertical take off from Water, while retaining in the design and mounting the required characteristics to permit of a.

horizontal take off or desired. j

A further feature of this invention is the o r landing ifv necessary embodiment of certain of the hereinbefore;

mentioned broad principles and characteristics of the' invention in an airplane of general conventional design to permit of a reduction in wing or supporting surface area and an increase in the vertical lift, while retaining a minimum'or relatively `low landing speed.` Thisl feature of the invention lvary the incidence angle so that the displacement flow acting lthereon creates an additional force having a vertical lift component and the downward flow of air on an aerofoil in the cslip stream of an angularly disposed propeller is eliminated. In order to compensate for the moment caused by the variation of the thrust force and maintainfiequilibriuin, this feature .of y the invention furvther provides for the simultaneous adjustinent of the horizontal stabilizing surfaces upon variation of the propeller thrust ancle. D With the foregoing, and certain objects i and results in view which will be readily till apparent to and iinders'toodby those skilled in thev aeronautical art from the following description and explanation, the invention consists in certain novel features in design and in construction, arrangements .and combinations of elements, yas will be more fully and particularly pointed out and specified hereinafter. 'l Referring to the accompanying drawing:

Figure 1, is a front elevation, more or less diagrammatical, of a vertical ascent airplane embodying the invention and equipped with pontoons or floats;

Fig. 2, is a view in sideelevation ofy the airplane of Fig. 1. 'c n Fig. 3, is a front elevation of a vertical ascent airplane similar to Figs. 1 and 2, but equipped with a wheeled landing 4gear and a 1modified forni of adjustable wing cellule.

Fig. 4, is. a detail view in end or side` elevation of the modified form otadjustable wing cellule shown in Fig. 3, a portion only of a body or fuselagebeing shown.4

Fig. 5, is a side elevationS of a modified application of certain principles of the "inventon and disclosing an angularly adjustable propeller and power unit, and an adjustable auxiliarywing cellule mounted in the pro eller displacement flow, parts being shown roken away and other parts in dotted outline.

Fig. 6, is a detail diagrammatical view of Lth adjustable power unitbed and operating 'mechanism, and of the adjustable stabilizer operatively connected therewith.

Fig. 7,' is a detail diagraininatical view in front elevation of the auxiliary adjust-v able wing cellule of Fig. 5 mounted on a fuselage.

Fig. 8, is a detail diagrammatical view of an adjustable power unit bed adapted forv use with a power unit of the radial or rotary types, a power unit of such type being indicated in .dotted outline mounted thereon.

Figs. 9 and 10, are diagrainmatical views of a modified type of airplane having the angularly adjustable propeller and power unit, and anadjustable lift surface or aerofoil mounted in the propeller -displacement ilow.

In Figs. 1 to 4 of the accompanying drawings, one possible aerodynamical and mechanical expressionof certain'df the broad principles and features of the invention is' disclosed as embodied in and presenting an airplane having certain of the' hereinbefore referred to general characteristics and capa` ble of vertical translational movement or vertical ascent and descent, andv of horizontal translational movement or horizontal flight. The illustrated forms and embodiments of the inventionare presented merely Vby way of examples and not of limitation,

for purposes of explanation and description to bring forth certain of the broad principles of the invention, and the application and results thereof. It will be clear and readily apparent to those familiar with this lart, from the following description and explanation, that these principles, and features are adapted to various other Vaerodynainical expressions and applications thereof, v other than the specificl examples as shown. y p l The `e`inbodiinent of the invention disclosed in Figs. 1 and 2 of the accompanying drawings, providesa verticall ascent airplane adopted for water use, and of a gen-- eral design which substantially conforms to the design of conventional airplane types for horizontal flight familiar. in this art,

and characterized by' a normally horizon tally disposed body or fuselage with the usual tail assembly or empennage and sup porting surface or wingfcellule mounted thereon.l In the example shown, the airplane comprises a streamline .body or fuseige 10v normally horizontally disposed and of general conventional design. A tail assembly or empennage is mounted in the usual manner at the after end of the fuselage and includes the vertical lin or stabilizer 11, vertical rudder 12 for directional 1control, and the horizontal stabilizer 'and push and pull tube 18 to the balanced elevator 14, and the rudder or foot bar 19 operatively connected with the vertical rudvder 12 by the control cables 20, all in the usual manner and for the purposes familiar large static thrust from power driven air` in this art.

A source -of power M, such as an internal combustion motor, lis in the present instance mounted inthe 'nose or forward portion of the fuselage 10, although the invention is not limited to such positionv and mounting. A

suitable source of fuel su ply to the motor M, such as the fuel tank shown in Fig. 2, is. mounted inthe fuselage 10 at any suitable or desired location thereon. The motor M is preferably of that type having a minimum weight per horsepower so as to permit of providing the airplane with maximum power while keeping the Weight of the power plant as low as possible. This is an important consideration in the design of an airplane in which itis desired to secure a screws or propellers to develop a vertical lift component, but canbe saidto be practically solved in the light of recent airplane motor developments in which power is developed at a low horsepower Weight, as well known to those familiar with'A the aeronautical and motor arts.

, Accordingto the invention, airscrews or propeller'sare'mounted to rotate around axes disposed approximately midway between the horizontal and the vertical although not so limited, and in the illustrated aerodynamical and mechaniwal adaptation of this characteristic of the invention two of such airscrews or propellers l? are mounted at opposite vsides of the nose or forward portion of the fuselage 10, andare dispsed for rotation in a plane inclined rearwardly with respect to .the normal horizontal position of the fuselage l0, approximately midway between the vertical and the horizontal, as clearly indicated in Fig. 2 of the accompanying drawings. In the exampleshown in Figs. 1 and 2 of the drawings the propellers P are operatively coupled to the motor M by means of the drive shafts 21 which extend outwardly and are inclined upwardly and forwardly' from the motor M in the fuselage 10. The

the respective gear housing, to form a substantia V supporting truss' therefor. The trusses formed from the struts 23 and carrying the gear housings 22 and propellers P are connected and braced by means of a rigid member 24 extending therebetween and lixed thereto, so that a rigid supporting frame is formed by the trusses and the brace member 24. A further V truss 25 is mounted converging upwardly from the fuselage 10 to the member 24 and serves to further brace this member and the frame of which it forms a part (see Figs. 1 and 3).

In this manner the propellers P are supported in fixedlposition on opposite sides of the fuselage 1() for rotation around an axis inclined upwardly and forwardly with rcspeet to the fuselage 10 approximately midway between the horizontal and the vertical, or at an angle of approximately 45 degrees, bythe drive shafts 21 operatively coupled t-o the motor M. .The propellers P are so mounted and arranged as tobe rotated in opposite directions to maintain the lateral and directional equilibrium of the airplane -in flight. The airscrews or propellers l are of the so called high efficiency type designed to deliver a maximum static thrust at a relatively low poweroutput, and each of the propellers P mounted in the position with respect to the normal horizontal position of the airplane as shown and described,.delivers 'a static thrust indicated in Fig. 2 of the drawings by the'thrust vector T, inclined approximately midway between the horizontal and the vertical and having a horizontal or tractive component,'and a vertical or lift component. 'lhe 'horizontal and vertical components of the propeller thrust 'l will each have a. value approximately 70% of the value of this thrust when inclined at au 10 aft of the propellers P and having a span and total gap such that the cellule as a unitlies substantially totally within the displacement low or so called slipstreams of the propellers P. The wings 26, 27 and 2 8 of the cellule lareiixed together in the desired gap relation as a unit by the outer inter-wing trusses 29, andthe inner interwing trusses 30, respectively, the latter being adjacent to' opposite sides of the fuselage 10. The inter-wing trusses 29 and 30, together with suitable brace wires 3l extending diagonally between and connecting the wings, formtherewith a rigid wing cellule unit having the requisite strength with minimum of parasite resistance. Fhe wingicellule so formed is mounted on the fuselage i 10 for angular adjustment as a. unit around 1 a horizontal 'axis longitudinally of the cellule to permit of varying the incidence angles,

of the wings or aerofoils forming the same, with respect to the direction of the displacementflow and the normal horizontal flight .attitude of. the airplane. The upper and lower wings 28 and 26, respectively, of the cellule are formed by continuous unbroken structures4 extending across the fuselage above 'and below thesame, and the intermediate wing 27 is vbroken and formed in two sections terminating inwardly at and adjacent oppos te sides of the fuselage 10 which extends therebetween, as shown in Fig. 1 of the drawings. The under side of the fuselage 10 is preferably cut away or formed to provide a transverse recess 32 (see Fig. 2) to receivel the lower wing 26, and the upperfwing 28 is cut away at the trailing edge portion thereof to form an openin i 33 (see Fig. 1) to'receive and fit over the upper side of the fuselage 10. In this manner the range of adjustment of the wing cellule secured at its opposite ends to the-wing celis increased and it is possible to retain continuous upper and lower wing structures with the advantages in strength resultlng therefrom. Furtherlthe vision of the pilot in cockpit 15 is increased by the trailing edge or rear opening 33 in the lupper wing 28.

In the specific example shown, the wing.

cellule .is mounted for angular adjustment around a horizontal axis vformed by a shaft 34 (see Fig. 1? extending transversely through the fuse age 10 and mounted and lule at points on the innerinter-wing trusses 30, respectively, intermediate the intermediate wing 27 and the upper wing 28. 'Any suitable bracing and 'supporting trusses can be formed in and as a part ofthe intervwing trusses 3() to receive and support the ends of the shaft 34, suchl for example `as the X truss indicated in Fig, 2 ofthe drawings for this pur ose.v The'wing Vcellule so mounted ,is provi ed with 'operating mecha- -nism for adjusting and setting the same from 'the control cockpit 15. As anjexampleo such mechanism, in' Fig. 2 of the drawings a control lever 35 1s shown mounted in the control `cockpit and pivotally coupled with the lower wing 26, or any other desired point of the wing cellule, by a push and pull rod or link 36. Suitable means for holding the wing cellule in the desired adjusted position, such D as the quadrant 37 which is engaged by the control lever 35 and .locks the latter in posil tion by any of a number of well known mech- KThe wing cellule is mountedon the fuse-f lage 10 so as to ,be substantially totally within and acted upon by the displacement iowv from the airscrews or propellers P. The displacement flow from the propellers P mounted as shown has certain characteristics which the present invention takes adthe upper and lower portions of the stream .is different from that at the central portion of the stream. Therefore'the inventionproi vides for mounting the aerofoils or wings of the wing cellule at an angle of incidence relative to the direction of that portion of the displacement flow in which mounted.

In accordance with this principle of the in# vention the aerofoils or wings 26, 27vand 28 of the wing cellule are mounted at an angle of .incidence relativev to the displacement flow, the direction of AWhichis indi-, cated generally in Fig. 2 ofthe drawings by the arrows from the tips of the propeller P, withthc result that.the upper wing28 is 'mounted at a, greater positive angle of incidence than theintermediate wing27-,while the lower wing 26.is 'mounted at substantially a negative angle of incidence with respect to the intermediate wing 27. This is clearly indicated in Fig. v2 of the drawings and is one of the basic features contributing to .the eiiiciency of the invention, as the maxl imuni .efficiency from the wings acted upon by the displacement stream is secured.

The wing cellule formed ofthe aerofoils orwings 26, 27 and 28 disposed in the displacement flow at normal angles of incidence lrelative thereto. as explained, is adjusted. around the axis of shaft 34 or its equivalent, so as to bring the .wings of the los l cellule at angles of incidence with respect to the displacement flow to secure maximum efficiency therefrom by the action` of the flow thereon. In the embodiment of the invention illustrated, this position of the wing cellule is shown in Fig. 2, in which the cellule assumes a rearwardly inclined angular position with respect to the normal horixzontal axis of the airplane, so the wings 26,

27 and 28 are all substantially spaced an equal distance rearwardly from the propellers P. With the airscrews or propellers P rotated by the motor Mtosecure maximum thrust T therefrom, the displacement flow or slipstreams thereof acts upon Wings 2G, 27 and 28 mounted in the flow land an additional force is created by the wing cellule from this action, due to the placing of the aerofoils in the displacement flow at angles of incidence thereto, as will be clear' to and understood by those familiar with the reaction from an aerofoil mounted at an angle of incidence to a ow or streamv of air acting thereon. This additional force so created is indicated in Fig.`2 of the drawings by the vector R, and the design and relative mounting and position on the fuselage 10 of the airscrews or propellers P and the wing cellule formed of the aerofoils or wings 26, 27 and 28, is' such that the propelresult that the equilibrium of the airplaneler thrust T and the force R created by the wing cellule in the displacement flow are approximately equal and balanced', with the in flight is established and maintained. The force R created by the wing cellule in the propeller displacement flow has a vertical'component which together with the vertical lift component from the angular position of the propeller thrust develops a resultant lift, indicated in Fig. 2 of the drawings by the ,lift vector L, which overcomes or overbalances the weight and resistance forces indicated by the vector WV, and permits of vertical translational movement or ascent, or by control of the power and thrust to equalize and balance the lift L and weight W, permits of sustentation or hoveringf with the vertical translational movement zero.

In this manner the invention solves the l y'problem of vertical lift in a more efficient and' practical manner than in the true heli- Copter type deriving direct vertical lift solely from the static thrust of an airscrew or propeller acting in a vertical' plane, as the resultant lift L of the invention is greater than the static thrust of the airscrews or propellers P acting alone, due to the addi- .tional lift created by the supporting surface formed by the wing cellule disposed in the displacement flow as shown and eX- plained. This feature of the invention perm-ts of vertical ascent and descent in an airplane conforming to the general .conventional designvof horizontal flight airplanes while retaining in the airplane the necessary characteristics required for normal horizontal flight, without the difliculties encountered in attaining horizontal flight with a true direct vertical lift or helicopter type.- In the einbodiment 0f the invention disclosed in Figs. 1 to 3, vertical flight is performed with the body or fuselage 10 in substantially normal horizontal attitude and the pilot in the control cockpit is in normal position with the full advantages in vision obtainedin horizontal flight. The tail assembly or control surfaces forming the conventional empennage and mounting thereof on the body 10 do not interfere with vertical flight as the balanced horizontal stabilizer 14 is mounted for movement to position in a vertical plane during vertical movements of the airplane, and the body or fuselage 10 being of streamline longitudinal contour will not offer prohibitive head resistance when moving in a lateral or sidewise direction, as will be clear to those skilled in ythis art.

The problem of horizontal flight and control in an airplane capable of flight in a vertical plane, is efliciently solved by the type of airplane as disclosed embodying the foregoing principles and design features of the invention. To secure horizontal translational movement the entire airplane can be tilted or nosed downwardly to increase thc horizontal or tractive components of the propeller thrust and simultaneously reduce the rear horizontal components of the wing cellule, or by angular adjustment of the displacement flow to reduce the rear horizontal components thereof. Further, by a combi- 100 nation of both the above operations of tilting the airplane forwardly and adjusting the wing cellule, horizontal translational movement can be secured, as will be apparent from the foregoing description and explana- 105 tion of the accompanying drawings. ln horizontal flight longitudinal equilibrium is secured by the ,proper projmrtioning and positioning of the acrofoils or wing cellule in the displacement flow and the relative 11u positioning of the other elements of' the airplane. to properly locate the center of gravity with respect to the other forces on the airplane. Further, longitudinal control and equilibrium is aided, by proper adjustment 115 of the wing cellule. It is to be` noted that the axis around which the wing cellule is rotatable, is not limited to the position shown, as any position structurally convenient to the wing cellule and fuselage may 12a be used. The locationof the axis of the angularly adjustable supporting surface or wing cellule will influence the control leverages and forces acting on the control mechanism, for example, in a mounting where 125 the force R passes through the pivot point control is balanced and should the thrust vector T also pass through the pivot point or axis, the angular adjustment of the wing cellule would have but small effect upon the 13o During horizontal Hight the displacement How will have a 'tendency t Hatten outand the Wing cellule can be adjusted to reduce the incidence angles and -thus increase the vertical component of the force R acting on the cellule. Lateral control in flight' is obtained through the provi-sion ofrtheusual ailerons 38 shown as mounted on they intermediate wing 27 of the wing cellule, although the invention is not limited to any particular mounting or type of lateral control medium.y The rudder 12 provides directional control, while the rotation of the propellers P in opposite directions maintains the airplane in lateral and directional equilibrium-or stability. Longitudinal control in horizontal Hight is secured by the balanced elevator'ld, aided .by angular adjustmentsof the wing cellule in the displacement How as previously referred to. The pilots seat 16 is preferably given a considerable rearward inclination so that with the body of the airplane tilted downwardly in horizontal Hight or in gliding, the pilot will be in anormal and natural attitude for proper Y control operation of the airplane.

From the foregoing it'will be apparent that by the proper design and structural applications and adaptations of the broad principles and features .of the invention, a`

type of airplane is provided capable of eiicient vertical ascent/or Hight, and of eHi cient horizontal Hight. Attention is here directed to the fact that the supporting surface or aerofoils disposed in the displacement How from the airscrews or propellers, are'not limited tothe number, arrangement or mounting disclosed by the wing cellule of the illustrated example, the essential fea- In the aerodynamical and mechanical cxyertical component from the angular 'direc-. tion of the thrust T establishes the resultant lift L to overcome the weight W. As illustrative of anethei""possible arrangement ofl supporting surface, the aerofoils'26 'and `28 are diagrammatically disclosed in dotment How so as to secure the required admanner herembefore ditional force R inthe explained.l

It is lobvious the angle of incidence of a wing may vary-throughout the span and the 4wing may also be set at a dihedral Iangley in accordance with common practice. Proper varying incidence would likely aftwist, this di lference is compensated.

The` vertical ascent type of airplane embodying the invention, is capable of vertical take oli' and vertical ascent, as well as vertical descent and landing. In vertical descent the power is controlled to reduce the thrust T and thereby reduce the' lift L to a point where the weight lV is greater' than and overcomes the lift, with the result that the airplane descends vertically but under coinplete control of the pilot. The rate of speed of this descent is readily controlled through varying the power applied to the propellers P from' motor M. In the event of power failure the ,airplane can be landed under control by gliding or volplaning in the usual manner employed with the conventional type of airplane, due to the characteristics and qualities retained by the design of the invention which control. y

In theairplane of Figs.v 1 and 2of the drawings, provision is made for taking 0H' permit'of horizontal flight and from and landing on water; and'consists of an undercarriage or landin` chassis of thel pontoon or float type. ,he desi n and mounting of these Hoats to permit o eiiicient vertical take olf and landing from and onto a body of water, and to further permit of a horizontal take off or landing if desired, is

another important fea-ture of .the invention.

pression of thisl feature disclosed in Figs. l

and 2, a single main.pontoon or Hoat 40 isv 'suspended below and spaced from the foror pontoon 42 is mountedv on a streamline ,structure 343 depending downwardly from 'thetail portion rof the fuselagev 10. The main pontoon or fiorite-:.0v is ot' relatively short length and a Width such as to protrude ine V trusses 41, 'in the usual or any -or extend a minimum distancelaterally beyond tie sides. of the fuselage thei'eabove, and is so positioned and mounted. as to be,

wing cellule thereabove. In this; manner headresistancefrom the Hout or pontoon 40 1n Avertical ascent 1sv reduced to Ia minimum.

The water vcontact surface 'of the pontoon 40 is-(preferably curved and arranged sous to re overcome ina vert'ical'talre `ojfffrom water to as low a value as possible. The depth of the pontoon 40 may be likewise made as uce the Huid .viscosity which must be' substantially covered bythe fuselage 10 and thereof to permit of making a horizontal take oil' or landing by planing on the surface of the water, as will be readily understood. The pontoons arenot limited to the shape above described, as for example, the main l pontoon 40 can have a V shape bottom in cross section as indicated by the dotted lines in Fig. 1 of the drawings, or the nose or for- Ward end can be of streamline shape as shown in dotted lines in Fig. 2 of the drawings. Under certain circumstances or conditions of operations, or of design, outrigged auxiliary pontoons or floats 44 can be provided on the main pontoon or float 40,- as indicated vin dotted outline in Fig. l of the drawings. VVith pontoons or floats properly designed it would be possible in case ot' necessity, to make a vertical landing on land with tha-airplane .of Figs. l and 2.

A modilie'd mounting and arrangement of the aerofoils or Wings 26, 2'( and 28 to form the wing cellule disposed in the displacement flow is shown in Fig. 3 of the drawings, tofgether with Fig. 4 inI which a multiplane celluleconsisting of four aerofoils or wings is shown so mounted. In this orm of',the wing cellule the aerofoils are individually .pivotally mounted to form a stationary truss wires 31, are seen, the longitudinals being enclosed within the contines of the wing covering. The struts 45 and 46 extend through the wings of the cellule whit'l are pivotcdthercto at the series ot` points 47 and 48, respectively. InFig. 4 a. four wing cellulel is shown together with a portion of the operating mechanism for rotating the wings on'their pivots. This mechanism is the same as employed for the triplane cellule of Fig. 3, and consists of a series of links 49 extending between and connecting adjacent wings ot the cellule, and the push and pull rod 36 pivotally connected with a wing of the cel-1 lule for operation by the control lever 35 in the cockpit hereinbefore described. Thus by actuating the rod 36, the wings of the cellule can be rotated on their pivots to change the angles of incidence in the displacement `flow forl an equivalent p urpose and results as explained 1n detail with respect to the rigid unit cellule of Figs. 1 and 2, of the drawlngs.

It is evident that in the foregoing type of truss, the interaerofoil links 49) may be located in relation to the individualy wing pivots (48) to vary'the relative angular operation of the individual wings. Furthermore by rigidly securing one or more aerofoils or wings and by disconnecting or removing their respective operating links, the same aerofoil or aerofoils may be non-operative and therefore fixed in relation to the axis of the airplane while the remaining operatively connected surfaces are actuated in thc usual manner. It is also contemplated that under certain structural conditions and arrangements, to wit: very large operative unbalanced areas; that arcas-or elementsl thereof be operated separately or collectively by separate individual control mechanisms, as disclosed hereinbefore to obtain a greater degree of controllability or to reduce forces imposed upon the control mechanisms.

" The airplane of Fig. 3 ofthe drawings embodying the invention, is provided with an undercarriage designed for landing use, which comprises the main forward chassis of more or less conventional design including the supporting trusses 50 and landing or ground wheels 5l and the rear or tail chassis comprising the landing wheel 52 mountedand supported upon the structure 43 ldepending from the rearlportion of the body in a manner previously referred to.

A modified application and embodiment of certain of the broad principles of the invenf tion hereinbefore described and explained, is disclosed in Figs. 5, 6, 7 and 8, of the accompanying drawings. As a specific example of this application, a conventional design and type ot airplane is illustrated, comprising the body or fuselage having the pilots cockpit (il and the tail assembly or empennage including the vertical lin`and rudder (i2, adjustable horizontal stabilizer G3 and elevator 64. A monoplane wing ot the parasol type having lateral control surfaces or ailerons 66 is mounted on and forms the supporting surface for the airplane, in the usual manner. Onefeature of this application of the invention resides in mounting the power plant or motor M and propeller P for angular adjustment as a unit topermit of varying the propeller thrust angle. This is accomplished by providing a motor bed 67 pivotally mounted on bearingsGS supported at opposite sides of the forward or nose portion of the fuselage 60 in the ixed trusses orAframes 69 thereof. The propeller P is mounted on and driven from the motor M in theusual or any desired manner so as to be movable and angularly adjustable therewith as a unit.

The mechanism for rotating the motor bed 67 on its pivots 68 to angularly. adjust the motor M and propeller P as vavunit is more orless diagrammatically illustrated in Fig. 6 of the drawings. An arcuate or curved rack bar 70 is fixed in vertical position at the rear or after end of the motor'bed 67 and meshes with a gear 71. A rack 72 is mounted for horizontal reciprocation and meshes with a gear 7 3 which is fixed to r0- tate with the gear 71 ih mesh with the motor bed rack 70. A link or push and pull rod 7 4 is pivotally coupled to and connecting the' rack 72 with the operating lever 75 mounted in .the pilotsl or control cockpit 61. Thus, by means of the lever 75, the rack 72 can be reciprocated to rotate the gears 71.. and 73 v to rotate the motor bed 67 fand angularly adjust the motor M and propeller Pas a unit,

-with the resulting variation or change in the direction of the propeller thrust. The normal horizontal position of propeller P to deliver a horizontal or tractive thrust is indicated by dotted lines in Fig. 5 of the drawings.

In accordance with the invention in the present embodiment thereof, auxiliary aerofoils forming wing cellules 76 are pivotally mounted at' 77 on and extending from opposite sides of the fuselage 10 in longitudinal alinement, beneath the monoplane wing in the propeller displacement fiow. A (See Figs. 5 and 7.) Suitable means similar to that described with reference to Figs. 1 and 2 including control lever 35 and link 36, is

provided for adjusting the wing cellules 76 to vary the angles of incidence thereof in the displacement flow. The aerofoils forming the wing cellules 76 are disposed in the. displacement fiow as hereinbefre described, that is, at angles of incidence `relative to the flow and not the axis of the propeller. In order lto compensate for the moment caused by the variation of the propeller thrust force about thecenter of gravity of the air lane, the adjustable horizontal stabilizer 63 isoperatively connected with either the motor bed 67 by operating cables 78, or b means of cables 78 to the control lever 75 see Fig.

6) mounted in the fuselage cockpit 61, so that adjustment of the motor and propeller P to vary the thrust angle with respect to the horizontalaxisof the airplane, results in simultaneous adjustment of the horizontal stabilizer to the proper angle to com ensate for the change in thrust direction, an maintain the equilibrium of the airplane under all conditions.

With an airplane embodying the foregoing features, the horizontal take off distance can be materially reduced by adjustin the propeller so -that the thrust is incline upwardly from 'and at an angle to the vertical to Ldevelop a vertical lift com onent, and by adjusting the wing cellule 76 1n the dis lacement fioms as to create Ia lift L in ad ition to the lift L ofthe' wing 65 and of the iter-j tical component of the propeller thrust. Further, it is possible to decrease the supporting surface area and increase the speed of the airplane, while retaining a safe and reasonable landing speed due to the angularly adjustable propeller Pand the adjustable wing cellules 76 mounted in the displacement iiow.- If desired the main supporting surface or wing 65 can be cut away at the leading edge portion in the dis lacement iow to reduce interference, as in icated in dotted lines in Fig. 5 of the drawings, or sweep forward wing provided.

The airplane of Fig. 5 is provided with the conventional design of undercarriage or chassis including the supporting trusses 79 and landing or ground wheels 80 mounted below the forward portion. of the fuselage, and the tail skid 81 mounted at the rear or tail portion of the fsela e. Due to the angularly adjustable prope ler P it -is possible to mount the landing wheels 80 inclose proximity to the fusela e 60 and thus shorten the trusses 79 an reduce head or parasite resistance which is a. considerable factor vin the conventionally mounted' chassis. .This is possible because in taking off and inI landing the propeller is in upwardly inclined position and ground clearance is obtained with the chassis mounted as described even where the normal horizontal position. of the propeller-P in iight would not give this clearance. This will be readily apparent by reference to the drawings in connection with the foregoin description. ,ReferringV to the angularly adjustable motor bed 67 with the motor M thereon, attention is directed to the fact that thebed is preferably pivotally mounted slightly forward of its center of gravity. It will be further noted that the cowl for the motor M is movable therewith in such a manner as to protectthe motor and streamline the same as much as. possible infall positions thereof. This is clearly shown by Fig. 5 of the drawings, as wellas Fig. 9'described hereinafter.

An angularly adjustable bed or mountv 67 formotors of the radial or rotary types is more or less diagrammatically illustrated in Fig. 8 of the drawings with such type of motor M' mounted thereon. The mounting and arrangement ofthe motor bed 67 is' analogous to that for the motor bed 6 7, with p the exception .that the bed 67 1n normal fixed at the forward lower im. l

of the accompanying drawings. In this embodiment an airplane including the more or less conventional design of body or fuselage 60 and biplane or semi-biplane wing cellule comprising the upper wing 82 and lower wing 83, the'upper wing being provided with the usual lateral control surfaces or ailerons 84, is shown. A landing chassis comprising the supporting trusses 85 and wheels 86 is mounted Bin the conventional manner on the fuselage 60, and a motor (not shown) andy propeller P are mounted for angular adjustment in the same manner as described with reference to the motor M and propeller P of Figs. 5 and 6. The motor cowl 87, diagrammatically shown in F ig. 9, is so formed and arranged as to move `with the motor to cover and streamline the same as much as possible in all positions of the motor and propeller P, as hereinbefore Yreferred to. The upper Awing 82 is cut away at the major portion of the leading edge within the displacement flow or slipstream of the propeller to form the rearwardly extending recess 88. The lower wing 83 has the central portion 89- thereof within the accordance with the principle of the invention explained in connection with the wing cellules 76Xof the airplane disclosed in Fig. 5. The position of the propeller- P and its axis and thrust in one position of adjustment, is diagrammatically indicated by broken lines in Fig. 9 of the drawings, and the position of the wing section 89 adjusted to position cooperating with the displacement flow from the propeller in adjusted vertically inclined position, is likewise indicated in dotted outline in this figure of the drawings. The operation and results obtainedV from the embodiment of the invention of Figs. 9 and 10, is similar to that explained and described in connection with the embodiment of Fig. 5, and consist essentially of an increase in speed in normal Hight, while retaining a relatively low landing speed, and a `decrease in the horizontal run re uired in taking off.

ttention is directed to the fact that the broad principles and features of the invention embodied and resented in the desi and arrangement o airplane disclosed in Figs. 1 to 3 of the drawings, are not limited to any particular number of arscrews or Lacasse propellers or the means for driving the same, or limited to any number or arrangement of aerofoils mounted in the displacement flow, as it will be recognized by those skilled in this art that these principles and features can be presented in a variety of ways other than disclosed inthe illustrated examples herewith. IVhile in the. example of the invention presented herein by Figs. l to3, the axis of propeller rotation is disclosed and referred to as approximately midway between the vertical and horizontal, the invention is not limited to any particular angle of propeller axis inclination in the broad aspects of the invention, as angles of inclination of any degree can be employed, and are contemplated by and included in the scope of the invention as set forth in the appended claims.

In the appended claims the term airplane is employed in a broad, generic sense to include any and all aircraft capable of embodying and presenting the broad prineipl'es and features of the invention, while the term, propellerls used in the claims for purpose of clearness and uniformity of expression, to include airscrews and all means or medium for developing a static thrust and displacement flow or stream of air.

It is also evident that various changes, modifications, variations and substitutions might be resorted to without departing from the spirit and scope of the invention, and hence I do not desire to limit myself to the exact disclosures' hereof.

Desiring to protect my invention in the broadest `manner legally possible, what I claim is:

1. In an airplane, laterally spaced propel- 1ers mounted to develop a combined thrust having a horizontal and a vertical component, and an aerofoil mounted with substantially the entire area thereof disposed in and subjected to the combined propeller displacement How, said aerofoil arranged at such an angle of incidence to the displacement iow,

and acted upon thereby to develop an additional force having a vertical component which together with the vertical thrust component establishes a resultant vertical lift capable of sustaining the airplane.

2. In an airplane, in combination, a propeller mounted to develop a thrust having a horizontal component and a vertical component, and an aerofoil mounted with the major area thereof in the propeller displacement flow and acted upon thereby to develop an additional force substantiallyv equal to and balancing the propeller thrust and having a vertical component,` which together with the vertical ,thrust component develops a vertical lift forsustaining the airplane. D

3. In an airplane, a propeller mounted to lll nent thereof to` cause horizontal translat1on of the airplane.

4. In an airplane, .a normally horizontally disposed fuselage, a propeller mounted to deliver a thrust having a horizontal component and a vertical component, a supporting surface for the. airplane mounted with substantially the entire areathereof in the propeller displacement flow and acted Aupon thereby to create an additional force substantially equal to and balancing the propeller thrust to maintain the airplane in lll equilibrium and having a vertical component which with the vertical thrust component develops a resultant vertical lift for vertical translation of the airplane with the fuselage in normal horizontal position. 4

5. In an airplane, a normally horizontally disposed fuselage, control surfaces mounted thereon, a propeller mounted to deliver a thrust having a horizontal component and a vertical component, a supporting surface for the airplane mounted in the propeller dis-l placement flow and acted upon thereby to create an additional force substantially equal to and balancing the propeller thrust to maintain the airplane in equilibrium, the additional force so created having a vertical component which together with the vertical component of the thrust develops a resultant vertical lift for vertical translation of .the airplane with the4 fuselage in substantially normal horizontal position, andA said control `surfaces operable to change the direction of the propeller thrust and increase the horizontal component thereof to cause horizontal translation of the airplane. i

6. In an airplane having a normally horizontally disposed fuselage, a supporting surface, and control surfaces; .apropeller mounted to deliver a thrust having a hori-v zontal component and a vertical component, the supporting surface for the airplane mounted in the displacement flow from the propeller andV acted upon thereby to create an additional force substantially ,balancing the propeller thrust, the additional force so created having a vertical component which combined with the vertical thrustcomponent develops a resultant lift of sucient magnitude to result in'vertical translation of the airplane, and the control surfaces so mounted that by operation thereof to tilt the fuselage and changethe direction of the thrust to increase the horizontal tractive component thereof the airplane is capable of horizontal translation with the control surfaces operative to control the .airplane during `sufh movement.

7 In an airplane, a propeller mounted to deliver a thrust having a horizontal component and a vertical component, and an aerofoil adjustably mounted with substantially the total area thereof in the propeller dis placement flow and acted upon thereby to ydevelop an additional force having a vertical component which With the vertical thrust component develops a resultant vertical hftI for vertical translation of the airplane, the.

said aerofoil adjustable to vary the angle of incidence thereof in the displacement flow and ,increase lthe horizontal thrust compo nent While reducing the vertical component to cause horizontal translation of the airplane.

8. In an airplane, a normally horizontally disposed fuselage, an empennage mounted thereon, a propeller mounted to deliver a a vertical component, and a sup orting surthrust` having a horizontal corponent and face disposed in the propeller isplacement flow and acted upon thereby to create anadditional force substantially balancing the propeller thrust and having a vertical com-- ponent which with the Avertical component of the thrust develops a resultant lift force for vertical translation of the airplane, the,

supporting surface adjustable "to vary the ang e of incidence thereof to the displace ment flow and reduce the force created there by tocause a horizontal translational movement of the airplane and the empennage operative for controlling the airplane during horizontal movement.

9. In an airplane a normally horizontally longitudinal and directional control surfaces, a` propeller mounted to deliver a thrust having a horizontal component and a vertical component, al supporting surface ',.for the airplane 4mounted in the propeller displacement flow and acted upon thereby ydisposed fuselage, an empennage including to create anadditional force having a vertical com onent which -together with the Vvertical t rust component develops a re-.

sultant verticallift for vertical translation of the airplane with the fuselage in substantially normal horizontal position, and the said supporting, surface adjustable to vary` the angle ofsincidence thereof in the dis.u placement flow and reduce the. force created thereby to increase the-'horizontal translational movement of the airplane, fthe 1011-..v

v gitudinal control surface of the empennage operable to cause change in uthe direction of thrust to further increase the horizontal thrust component and tractive effect thereof, andthe control surfaces of the empennage operable vto control the airplane during .horizontal movement.

10"." In an airplane including a normally horizontally disposed9 fuselage, a propeller J kto the propellerthrust force and main- .taining the airplane in longitudinal equi librium.

i 11. In an airplane including a normally horizontally disposed fuselage, a propeller .mounted to deliver a thrust at an angle to l the longitudinal axis of the fuselage and horizontal position, the said supporting surface adjustableto change the incidence angle .porting surface adjustab having a vertical component and a horizontal component, and a supporting surface disposed in the propeller displacement flow at an angle of incidence such that an additional force is created substantially equal to the propeller thrust and having a vertical lift component which with the vertical thrust component develops a resultant lift force capable of imparting vertical translational movement to the airplane and the said suple to vary the angle of incidence in the displacement iow and change the magnitudeof the additional forceicreated thereby. y

12.` In an airplane, a propeller mounted to deliver a thrust having a horizontal component and a vertical component of substantially equal magnitude, and an aerofoil disposed in the"'propeller displacement flow at an angle of incidence thereto for developing an additional force substantially equal to the thrust force and maintaining the airplane in equilibrium, the aerofoil adjustable to change the angle of incidence and reduce the additional force below the magnitude of the thrust force.

13. In an airplane, a normally horizontally disposed fuselage, an empennage, a snpporting surface, a propeller mounted to deliver a thrust at an angle inclined upwardly to the longitudinal axis of the fuselage, said supporting surface mounted in the propeller displacement iiow at an angle of incidence theretfto develop an additional lforce having a lift component which with the thrust lift component imparts vertical translation to the airplane with the fuselage in normal thereof in and to the displacement flow and reduce the lift component thereof, and said Aempennage operable'to incline the longitudinal axis from normal position and increase the horizontaltractive effect of the propeller thrust for horizontal translation of the airplane.

14. In an airplane, a propeller mounted with the axis thereof inclined upwardly and forwardly from the horizontal, and a wing cellule composing a series of aerofols disposed in the propeller displacement flow at angles of incidence relative to the flow acting thereon, respectively, the wing cellule so disposed creating a force substantially equal to and balancing the propeller thrust force.

15. In an airplane, a propeller mounted lo deliver a thrust acting in a. direction approximately midway between the vertical and the horizontal, and a wing cellule coin- Iprising aerofoils disposed in the propeller displacement flow at angles of incidence relative to the flow acting thereon, respectively, said aerofoils adjustable to vary the angles of incidence relative to the flow and adapted at certain angles of'incidenee to create a forceA by the action of the iow thereon substantially equal to and balancing the propeller thrust force.

16.'In an airplane,a propeller mounted to deliver a thrust acting in a direction substantially midway between the horizontal and the vertical, and a supporting surface disposed in the displacement flow at an an gle of incidence relative to the iow acting thereon, said supporting surface adjustable to vary the angle of incidence to the ow and adapted at a certain angle of incidence to create a force substantially equal to and balancing the propeller thrust force, while at cert-ain other angles of incidence creating a force less than the thrust force.

17. In an airplane, a normally horizontally disposed fuselage, propellers mounted at opposite sides of said fuselage to rotate in opposite directions and maintain the lateral equilibrium of the airplane, said propellers mounted on axis inclined upwardly and forwardly at an angle to the longitudinal. axis of the fuselage, a supporting surface adjustably mounted on the fuselage and having the major area thereof disposed in the displacement flow from said propellers and creating a force by the action of the flow thereon substantially equal to and balancing the thrust force developed by the propellers, the force created by the` supporting surface and thev propeller thrust force having vertical lift components which combined develop a resultant lift for imparting vertical translational movement to the airplane.

18.In an airplane, a normally horizontally disposed fuselage, propellers mounted at opposite sides of the longitudinal axes thereof to rotate'z in opposite directions and maintain the lateral equilibrium of the air f area thereof disposed in the propeller Losanna plane, said propellers mounted on axis inclined upwardl forwardly to an angle to the normal orizontal axis of the fuselage, a supporting surface adjustably mounte on the fuselage and having the ma'pr 1S.- placement flow at an an le of incidence relative to the flow acting t ereon -andcreating a force by the action of the iow thereon sub- A staintially equal to and balancin the propeller thrust force to maintain tige longitudinal equilibrium of the airplane, 'thel force v created by the supporting surface Aand the propeller thrust forcereach, having a vertical component which combined develop a resultant vertical lift for vertical translation of the airplane with the fuselage in substantially normal horizontal position, the said lsupporting surface adjustable for va ing' the an le of incidence to reduce the orce create thereby below the thrust force and thereby increase .the tractive effect of the thrust force for horizontal translational movement to the airplane. l

'19.1 In an airplane,a propeller mounted to deliver a thrust having a vertical component and a horizontal component, an 'aerofoil disposed in the propeller displacement wilow and acted'v Upon therebyto" create an additional forcehaving a horizontal compo- 'nent acting in a direction) opposite to the horizontal thrust component and substantially balancing the same. l c

20. In-an4 airplane, a propeller mounted to deliver a thrust having a vertical component and a horizontal component, an aerofoil disposed with the major' area thereof in the 'propeller displacement flow at an' angle of incidence thereto and acted upon thereby to create aforce having a vertical component and a horizontal component, the horizontal component of the force created by the aerofoil acting in a direction opposite to the horizontal pro `eller thrust but substantially equal to and alancing the same,.and the combined vertical components of said force and the ropeller thrust developing avertical lift or impartin vertical translational movement to the airp ane.

21. An airplane of the vertical ascent type, embodymg a propeller and a supportsurface mounted disposed within the propeller displacement flow andacted upon thereby so as to deyelo naerofoil forces substantially vequal to an' balancing the propeller thrust forces to sustain the airplane, and means for tilting the airplane in flight to shift the position of the propeller and' supporting surface `forces to cause substanv- :la

tial horizontal translational movement of the air lane.

22 n an airplane, propellers mounted in viriedfposition-to deliver a thrust having a vertical component and a horizontal component, a supporting surface disposed with the major area thereof in the displacement flow' from said propellers and acted upon thereby to create an additional force substantially .balancing the propeller thrust, and saidsupportin surface adjustable. independently of sai propellers to vary the angle of incidence thereof in the displacement flow., j Y

23. In an airplane, a normally horizontally disposed fuselage, propellers mounted thereon iniixed position to deliver a thrust having ae vertical component and a horizontall component, a supporting surface mounted onfsaid fuselage disposed with the major area within and acted upon by the propeller displacement iiow to create an additional force substantially balancing the propeller thrust, 'and said supporting surface adjustable on the fuselage independently of said propellers to vary its angle of incicgence in the flow and vary the force created thereby. j

V24. In an airplane, a fuselage, propellers mounted on opposite' sides thereof in fixed position to deliver a thrust having a vertical i component and a horizontal com-- ponent, a supporting surface mounted on the fuselage with its major area within and acted upon by the propeller displacement flow to create a force substantially balancin the propeller thrust, and the said aerofo adjustable on the fuselage independently of the propellers to change its angle of incidence and reduce the force created thereby.

25. In' an airplane, a normally horizontally dis .osed fuselage, a truss structure extendin rom oppositey sides of said fuselage, propel ers mounted on said truss-structure disposed at opposite sides of said fuselage in fixed positlon for rotation around axis inclined upwardly and Aforwardly to the horizontal, drive mechanism for said propellers, a supporting surface mounted on the fuselage in position with the major area thereof dispose within and acted upon by the displacement flow from said propellers, and the said supporting surface adjustable independently of the propellers and drive` mechanism therefor to vary the angle of incidence thereof in the dis lacement iow. Signed at Ithaca, New Ork, this 18th day o f August, 1923i r j .RANDOLPH F. HALL. 

